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The nature of flow in the systemic venous pathway measured by magnetic resonance blood tagging in patients having the fontan operation  Mark A. Fogel,

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Presentation on theme: "The nature of flow in the systemic venous pathway measured by magnetic resonance blood tagging in patients having the fontan operation  Mark A. Fogel,"— Presentation transcript:

1 The nature of flow in the systemic venous pathway measured by magnetic resonance blood tagging in patients having the fontan operation  Mark A. Fogel, MD, FACCa,c, Paul M. Weinberg, MD, FACCa, Alison Hoydu, PhDc, Anne Hubbard, MDc, Jack Rychik, MD, FACCa, Marshall Jacobs, MDb, Kenneth E. Fellows, MDc, John Haselgrove, PhDc  The Journal of Thoracic and Cardiovascular Surgery  Volume 114, Issue 6, Pages (December 1997) DOI: /S (97) Copyright © 1997 Mosby, Inc. Terms and Conditions

2 Figure. Fig. 1A. MRI protocol to obtain a bolus tag image
Figure. Fig. 1A. MRI protocol to obtain a bolus tag image. Spin-echo images are obtained parallel to blood flow in the SVP (upper left and upper center panels). Saturated spins along a single plane produced a tag that was placed in the SVP just above the IVC-RA junction (not shown), in mid-baffle (not shown), and in the SVC (upper right panel). The movement of blood displaces the saturation band laid down across the vessel (arrowheads), whereas stationary structures such as the chest wall and spine (arrows) maintain the saturation band laid down at its original position. The lower panel depicts image analysis (image is magnified). Both the upper right panel and lower panel are respiratory gated images. Each image is analyzed by tracing both the anterior wall (AW) and posterior wall (PW) of the vessel, the stripe where the tag was laid down (baseline), and the stripe that was moved by the motion of the blood (flow curve) as shown on the right panel. At twelve equally spaced points across the diameter of the vessel, we calculated the path of the blood from the initial position of tagging to the point where blood moved the tag (the lower panel shows only three positions for simplicity, represented by arrows with split tails). P, Posterior; PA, pulmonary artery; S, superior; Vent, ventricle. The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /S (97) ) Copyright © 1997 Mosby, Inc. Terms and Conditions

3 Figure. Fig. 1B. Bolus tagging in the SVP
Figure. Fig. 1B. Bolus tagging in the SVP. The nine-panel image on the left displays flow in the SVC at 50 msec intervals throughout the cardiac cycle. Note that the tag over the SVC (arrowhead) persists and moves on all nine images. Arrows display where the tag is initially laid down. The panels on the right are magnifications of the SVC at maximum (max) flow (upper panel) and minimum (min) flow (lower panel). Arrowheads and white lines outline the baseline and flow curve. The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /S (97) ) Copyright © 1997 Mosby, Inc. Terms and Conditions

4 Fig. 1C A comparison of bolus tagging versus phase-encoded velocity mapping(VMAP). Velocity is plotted on theY axis and phase of the cardiac cycle is plotted on theX axis (1 = beginning, 10 = end of the R-R interval). Both curves were generated at the same tagging level in the same patient within 5 minutes of each other. Note that the curves are almost superimposable. The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /S (97) ) Copyright © 1997 Mosby, Inc. Terms and Conditions

5 Fig. 2 Bolus tagging and flow in the SVP. A, This figure is representative of data from one patient of the geometry of the velocity profile. This graph of velocity versus position across the SVP displays the velocity profile at all phases of the cardiac cycle (each curve represents a different phase of the cardiac cycle, with 1 = at R wave and 14 = just before the next R wave). B, This figure is representative of data from one patient, which graphs velocity versus time (from R wave to R wave). The family of curves represent the twelve positions across the SVP diameter that were measured, with 1 = most posterior and 12 = most anterior. The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /S (97) ) Copyright © 1997 Mosby, Inc. Terms and Conditions

6 Fig. 2 Bolus tagging and flow in the SVP. A, This figure is representative of data from one patient of the geometry of the velocity profile. This graph of velocity versus position across the SVP displays the velocity profile at all phases of the cardiac cycle (each curve represents a different phase of the cardiac cycle, with 1 = at R wave and 14 = just before the next R wave). B, This figure is representative of data from one patient, which graphs velocity versus time (from R wave to R wave). The family of curves represent the twelve positions across the SVP diameter that were measured, with 1 = most posterior and 12 = most anterior. The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /S (97) ) Copyright © 1997 Mosby, Inc. Terms and Conditions


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